AB1449 THE GENETIC DIVERSITY AND FEATURES OF TREATMENT OF JUVENILE IDIOPATHIC ARTHRITIS
Authors: S. Vardanyan, V. Vardanyan, A. Sargsyan, N. Manukyan, K. Ginosyan
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Juvenile idiopathic arthritis (JIA) is the most common chronic arthritis of childhood. Systemic JIA has many clinical features overlapping with familial Mediterranean fever, and MEFV gene mutations play a critical role in genetic background for JIA and influence the severity of the disease. <h3>Objectives</h3> 1.To find out associations between different immunological abnormalities, HLA-B27-positivity, carriage of familial Mediterranean fever (FMF) mutations, and clinical polymorphism of JIA. 2.To evaluate the effectiveness of treatment with DMARDs and NSAIDs. <h3>Methods</h3> 94 patients with confirmed JIA (100% male, mean age 14±2 years) were included in the study. All patients corresponded to ILAR criteria. 28 (29.8%) were treated with only NSAIDs, 66 (70.2%) with NSAIDs and sDMARDs (33/50%/ methotrexate, 33/50%/ sulfasalazine), 9 (13.6%) - with bDMARDs. The data is introduced as odds ratios (OR) with 95% confidence interval (CI). The results were considered significant when p&lt;0.05. <h3>Results</h3> At baseline 17 (18.1%) patients were classified as a systemic, 13 (13.8%) - oligoarticular, 3 (3.2%) - polyarticular RF-positive, 8 (8.5%) - polyarticular RF-negative, 3 (3.2%) - psoriatic, 49 (52.1%) - enthesitis-related JIA. MEFV gene mutations were observed in 38 (40.4%) patients (35/92.1%/ - one heterozygous mutation, 3/7.9%/ - more than one mutation), FMF was diagnosed in 3 (3.2%) patients. We found positive significant association between MEFV carriage and systemic JIA (OR/CI95%/=10.3/2.7-39.2, p&lt;0.01), as well as polyarticular RF-negative JIA (OR/CI95%/=5.3/1.5-10.6 p&lt;0.05). Despite the MEFV carriage, colchicine was prescribed to only 5 (5.3%) patients. 28(29.8%) patients were HLA B27- positive and we found positive significant association between HLA B27-positivity and olygoarticular JIA (OR/CI95%/=5.6/2.3-15.7, p&lt;0.05), as well as enthesitis-related JIA (OR/CI95%/=13.6/3.2-19.4/, p&lt;0.01). Sacroiliitis was diagnosed in 85 (90.4%) patients, 26 (30.6%) – non-radiographic, 59 (69.4%) - radiographic. The rise in progression from non-radiographic sacroiliitis to radiographic significantly decreased in patients on methotrexate (OR/CI95%/=0.05/0.001-0.044/, p&lt;0.01), compared to sulfasalazine (OR/CI95%/=0.78/0.36-2.79 p&gt;0.05). For patients on DMARDs the disease had a self-limited course, without clinical manifestation in adulthood. Total remission was mostly associated with methotrexate (OR/CI95%/=13.5/1.6-95 p&lt;0.01), in contrast to sulfasalazine (OR/CI95%/=0.69/0.28-1.72 p&gt;0.05). <h3>Conclusion:</h3> 1.The carriage of MEFV gene mutations increase the risk of manifestation of polyarticular and systemic JIA. 2.Early appointment of DMARDs together with NSAIDS makes it possible to stop the disease and prevent its transition to adult rheumatology. 3.Despite recent ACR treatment guidelines recommending NSAIDS and sulfasalazine for the treatment of sacroileitis, early administration of methotrexate also prevents the transition of nonradiographic sacroileitis to radiographic. <h3>References</h3> [1] Zhong, L., Wang, W., Li, J. et al. The association of MEFV gene mutations with the disease risk and severity of systemic juvenile idiopathic arthritis. Pediatr Rheumatol <b>18</b>, 38 (2020). https://doi.org/10.1186/s12969-020-00427-8 [2] Angeles-Han ST, Ringold S, Beukelman T et al. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Screening, Monitoring, and Treatment of Juvenile Idiopathic Arthritis-Associated Uveitis. Arthritis Care Res (Hoboken). 2019 Jun;71(6):703-716. doi: 10.1002/acr.23871. Epub 2019 Apr 25. PMID: 31021540; PMCID: PMC6777949. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.